Experimental assessment of the pathogenicity of two avian influenza A H5 viruses in ostrich chicks (Struthio camelus) and chickens

Living with disease? Biosecurity and avian influenza in ostriches

“…Scientific research on avian influenza in ostriches has confirmed the complexity of the disease in this large poultry species (Clavijo et al 2003;Cooper et al 2004;Manvell et al 1996Manvell et al , 1998Panigrahy et al 1995). A key finding of these studies was that high and low pathogenic strains of avian influenza affected ostriches in similar ways.…”

Field and laboratory findings of the first incursion of the Asian H5N1 highly pathogenic avian influenza virus in Africa

“…Moreover, data collected from ostriches highlights their unusual behaviour to HPAI infection, including the H5N1 virus. Other reports of natural and experimental infection (Manvell et al ., 1998;Capua et al ., 2000;Olivier, 2006) had already described the total or partial resistance of these birds to clinical disease, despite the virulence of the strain, as assessed conventionally in chickens. Ostriches could therefore play a role in avian influenza epidemiology in Africa, acting as healthy carriers of H5N1.…”

Serological investigation of highly pathogenic avian influenza H5N2 in ostriches (Struthio camelus)

“…This implies that AIV spreads much more rapidly between ostriches than previously reported (Oliver, 2006) and we propose that the most likely primary route of transmission is through the watering troughs where the ostriches congregate, as opposed to the faecalÁoral route. Shedding of H5 was detected from both tracheal and cloacal swabs during the outbreak (Abolnik et al, 2012) but other studies have shown that ostriches shed AIV from the trachea for longer periods, and that, of the two sources of samples, successful isolations are made more frequently from the trachea (Manvell et al, 1998;Clavijo et al, 2003). Ensuring that drinking water is adequately disinfected may thus be the single most important method of preventing AIV from spreading within an ostrich flock, but this remains to be demonstrated experimentally.…”

“…Farmed ostriches (Struthio camelus) are classified as poultry by the World Animal Health Organization (OIE) and the European Union, and are thus subject to the reporting and control procedures that apply to NAI (Toffan et al, 2010). Unlike other poultry, however, adult ostriches show few clinical signs following infection with HPAI and mortality is usually low even when the infecting strains are highly pathogenic in/virulent to chickens (Manvell et al, 1998(Manvell et al, , 2003Capua et al, 2000;Olivier, 2006). Ostriches younger than 6 months may show clinical signs that include respiratory difficulty, green urine, depression, acute hepatitis, peritonitis and mortality.…”